1. Field of the Invention
The present invention concerns a method for the determination of dicyanodiamide in plants or parts of plants, especially in cereals.
2. Prior Art Statement
The use of dicyanodiamide as a treatment material for plants is well known. For environmental protection reasons it is desirable to determine accurately the residual content of dicyanodiamide in these plants.
Up to now, analytical methods for the determination of small amounts of dicyanodiamide have been based either on photometric methods (cf. Zeitschrift Pflanzenernahrung Bodenkunde (J. Plant Nutrition Soil Science) 147, 268 (1984) or Landwirt. Forschung (Agricultural Research) 39, 20 (1986)) or on thin layer chromatographic methods (cf. CA 105, 178 074b).
In the photometric determination, the dicyanodiamide is detected by means of a color reagent, so that there is a problem with interfering impurities, especially when the determination must be undertaken in plants. The elimination of the plant matrix, as also in thin layer chromatographic methods, represents a problem that is solved only with difficulty, so that the sensitivity of detection and also the reproducibility are in no way satisfactory.